Known in the prior art is a rotation angle detector wherein, in order to detect the rotation position of a rotor, single-phase excitation coils are wound respectively around each of a plurality of teeth of a stator, and furthermore, two-phase output coils are wound alternately around the teeth where the excitation coils are wound, the total number of windings of the two-phase output coils is the same value of N (where N is a positive integer).
However, in a conventional rotation angle detector of this kind, error in detection of the rotation position occurs due to manufacturing errors in the stator, and the like. In the prior art, a rotation angle detector has been proposed in which, in order to reduce detection errors in the rotation position of the rotor, the number of windings of an output coil of one phase, among two-phase output coils, is kept at N, and the number of windings of the output coil of the other phase is adjusted to N±m (where m is a positive integer and N>m) (see, for example, PTL1).